#单分支if语句
#函数的功能：将字符串str当成有效的表达式来求职并返回计算结果
score=eval(input("请输入成绩分数:"))
if score >= 60:
    print("成绩已及格")

#分别输入58  75 87 100 进行测试 60 80 90 100
score = eval(input("请输入成绩分数"))
if score <60:
    print("成绩不及格")
if 60<= score<80:
    print("成绩一般")
if 80<=score<=90:
    print("成绩良好")
if 90<score<=100
    print("成绩优秀")

#嵌套if分别输入88 99 进行测试
score =eval(input("请输入成绩分数"))
if 60<=score:
    print("成绩已及格")
    if 90<score<=100:
        print("成绩优秀")

# score = eval(input("请输入成绩分数:"))
# if 60<=score
#     print("成绩已及格")
#     if 90 <=score<=100
#         print("成绩优秀")


# a = eval(input("请输入a的值："))
# if a > 20:
#     print("变量a大于20")
# else:
#     print("变量a不大于20")


# score =eval(input("请输入成绩分数："))
# if score>=60:
#     print('成绩及格')
#     if score >= 90:
#         print('成绩很好')
#     else:
#         print('成绩一般')


# score = eval(input('请输入成绩分数：'))
# if score >= 60:
#     print('成绩及格')
#     if score >= 90:
#         print('成绩很好')
#     else:
#         print('成绩一般')
# else:
#     print('成绩不及格')
#     if score < 30:
#         print('成绩极差')
#     else:
#         print('成绩较差')

a=eval(input('请输入年份：'))
if a%4==0 and a%100!=0 or a%400==0:
    print('是闰年')
else:
    print('不是闰年')





score =eval(input('请输入成绩分数：'))
if score >= 90:
    print('成绩优秀')
elif score >=80:
    print('成绩良好')
elif score >=70:
    print('成绩中等')
elif score >=60:
    print('成绩较好')
else:
    print('成绩不及格')

# for i in  ["1","2","3","4","5"]:
#     print('上班时间为：',i)
#
#
# for i in  range(1,11):
#     print(i, end=" ")
#     print()
# for i in  range(1, 11, 2):
#     print(i, end=" ")
#     print()
# for i in  range(1, 7, 2):
#     print(i, end=" ")
# #
# #
i = 1
while i < 10:
    j = 1
    while j <= i:
        print("%d*%d = %d"%(j,i,j*i),end = "  ")
        j+= 1
    print("")
    i+= 1


# sun = 0
# for i in range(1, 101):
#     sum+= i
#     print(sun)
#
#
# for i in ["1","2","3","4","5"]:
#     print("上班星期为：",i)
#     t = 9
#     while t <= 17:
#         print("时间段：",t)
#         t = t+1

# i=1
# while i <= 5:
#     print("上班星期为：",i)
#     i = i+1
#     t = 9
#     while t <= 17:
#         print("时间段：",t,end=" ")
#         t = t+1

#
# for i in  range(1,6):
#     print("上班为周：",i)
#     for t in range(9,18):
#         print("时间段为:",t,end="  ")
#     print()


while i <= 5:
    print("上班时间为:",i)
    i = i+1
    t = 9
    while t <= 17:
        print("时间段:", t)
        t = t+1

while i <= 5:
    print("上班星期为：", i)
    i = i + 1
    for t in ["9","10","11","12","13","14","15","16","17"]:
        print("时间段：", t)


i = 1
while i < 10:
    j = 1
    while j <= i:
        print("%d*%d = %d"%(j,i,j*i),end = ' ')
        j += 1
    print("")
    i += 1    

i = 0
while i <= 5:
    i += 1
    print('星期为：', i)
    if i == 3:
        break

i = 0
while i <= 5:
    if i == 3:
        break
    print('星期为：', i)
    i += 1


for i in  range(1, 6):
    print("星期", i)
    if i == 3:
        break


for i in range(1, 6):
    if i == 3:
        break
    print("星期", i)


i = 0
while i < 5:
    i = i + 1
    if i == 4:
        continue
    print("星期", i)


for i in range(1, 6):
    if i == 4:
        continue
    print("星期", i)    